Modal Shares of Key Criteria Pollutants From Transportation Sources: 1997
Key: CO=carbon monoxide; NOx=nitrogen oxides; PM-10=particulate matter 10 microns in diameter or smaller; VOC=volatile organic compounds.
NOTES: Other nonroad includes recreational vehicles, recreational marine vessels, airport service vehicles, and railroad maintenance equipment. Does not include farm, construction, industrial, longging, light commercial, and lawn and garden equipment.
SOURCE: U.S. Environmental Protection Agency, Office of Air and Radiation, Air Quality Planning and Standards, National Air Pollution Emission Trends, 1990-1997, available on the EPA website at www.epa/ttn/chief/trends97/emtmd.html.
